A wireless network generally includes several Access Nodes (ANs) and several user equipments (UEs). In wireless networks the user equipments have different operation modes (OMs) depending on the type of data that is being transmitted and/or received. An operation mode can e.g. be a set of procedures that specify the functionalities of the user equipments in order to ensure the correct data transfer between the network and the user equipments. The type of data may here refer to the different characteristics of data traffic in terms of inter-arrival times, burstiness, etc. The different operation modes may also account for the case where neither transmissions nor receptions have been scheduled for a particular user equipment.
One such operation mode is a discontinuous reception (DRX) mode. The DRX mode aims at saving energy of the UE by turning the receiver off during the instants of time where there is no data to be received. Hence, the design of the DRX mode depends on the type of data to be received, and/or on the frame structure of the wireless network.
In conventional solutions, the DRX schemes have not been optimized for bursty data and short packet transmissions, such as transmissions over short subframes. Such transmissions over short subframes may include e.g. voice calls, video streaming and web browsing transmissions. For example, in conventional Long Term Evolution (LTE) solutions, the length of the opportunity for DRX in voice data is more significant during the periods when the person receiving the call is speaking than during silent periods. Typically, a Voice over internet protocol (IP) (VoIP) packet inter-arrival time is 20 ms during speaking periods. During silent periods, the Silence Description (SID) packets used to generate comfort noise in real systems are assumed to be generated on 160 ms intervals.
Another limitation of conventional DRX solutions in LTE is the long wake-up latency when a UE is in idle mode. In LTE, the UE has to perform random access procedure and obtain a Radio Resource Control (RRC) connection again when a UE is woken up from idle mode by means of a paging procedure, which takes time.